Air velocity actuated electrical switch



July 1, 1958 s ow 2,841,667

AIR VELOCITY ACTUATED ELECTRICAL SWITCH Filed Jan. 18, 1957 INVENTOR.

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ATTD RN EYE United States Patent 2,841,667 AIR VELOCITY ACTUATED ELECTRICAL SWITCH Glenn E. Stowe, Farmington, Maine Application .lanuary 1 8, 1957, Serial Nb. 634,991 4 (Ilaims. (Cl. 200"81.9)

This invention relates to an electrical switch, and more particularly to an electrical switch which is actuated by air.

The object of the invention is 'to provide a switch which is constructed so that the passage of air or other gaseous medium therethrough will serve to actuate the switch whereby electrical circuits can be readily controlled.

Another object of the invention is to provide an air velocity actuated electrical switch which includes a Venturi that is provided with a throat therein, so that as air passes through the Venturi, a vacuum will be created which can be used to move a ball that controls the flow of current through various electrical circuits.

A further object of the invention is to provide an air actuated electrical switch which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is a longitudinal sectional view taken through the air actuated electrical switch, constructed according to the present invention.

Figure 2 is a sectional view illustrating one of the contacts.

Figure 3 is a plan view of the contact shown in Figure 2.

Figure 4-is a sectional view taken on the line 4-4 of Figure 1.

Referring in detail to the drawings, and more particularly to Figure 1 of the drawings, the numeral indicates a Venturi which includes an intermediate narrow portion 11 that defines a throat 12, and the ends 13 of the Venturi 10 are enlarged and open whereby air or other gaseous medium can readily pass therethrough as shown by the arrows in Figure 1. The throat portion of the Venturi 10 is provided with an orifice or opening 14, for a purpose to be later described.

Formed integral with the Venturi 10 or secured thereto, is a hollow housing 15 which may have a cylindrical shape as indicated in Figure 4, and the housing 15 and Venturi 10 may be made of a suitable material which does not conduct electricity. The housing 15 is provided with opposed bushings 16 and 17, and contact bars 19 and 18 are seated in or mounted in the bushings 16 and 17. The housing 15 further includes a pair of opposed bushings 20 and 21, and metal contact bars 22 and 23 are supported by the last named bushings 20 and 21. A suitable securing element such as a bolt 24 extends through the outer portion of each contact bar, and a conductor wire 25 is connected to each bolt 24.

The lower end of the housing 15 is provided with a neck 26 that has an opening or vent 27 therein, and the intermediate portion of the housing 15 is provided with an aperture or bleed opening 28, for a purpose to be later described.

The inner portion of each of the contact bars is beveled or tapered as at 29, and movably mounted in the housing 15 is a spherical body member or ball 30 which is made of metal. A coil spring 31 engages a portion of the body member 30, and the coil spring 31 is interposed between the body member 30 and the bushings 16 and 17.

From the foregoing, it is apparent that there has been provided an air operated or air actuated electrical switch. In use, as the air passes through the Venturi 10, it will be seen that the air will pass through the reduced diameter throat 12 so as to create a vacuum in the vicinity of the orifice 14. This will cause air to be sucked in from the space 32 whereby the spherical body member .30 will be sucked or pulled toward the Venturi 10. With thebody member 30 in the position shown in Figure 1, it will be seen-that the metal body member 30 establishes contact between the pair of bars 22 and 23 so that an electrical circuit is completed through the cor responding wires 25. However, when air of sutficient velocity passes through the Venturi 10 so as to lift or move the body member 30 away from the bars 23 and 22', then the electrical circuit which is connected to the bars 22 and 23 will be broken or disconnected. At the same time, the spherical body member 30 will compress the spring 31 and the. body member 30 will move into engagement with the bars 18 and 19 whereby an electrical circuitconnected to the bars 19 and 18 will be completed. It is to be understood that these circuits may be hooked up to any desired type of apparatus or mechanism. When the velocity of the air passing through the Venturi 10 decreases below a predetermined level, the spring 31 will return the body member 30 and associated parts back to the position shown in Figure 1 whereby the metal body member 30 will again complete the circuit between the bars 22 and 23, and at the same time disconnect the circuit between the bars 18 and 19. As previously described, the inner end portions of the bars are beveled or tapered as at 29 so that as the body member 30 moves into engagement with these tapered surfaces, a good contact Will be made.

The Venturi 10 and housing 15 are made of a material which will not conduct electricity, while the bars and body member 30 are made of a suitable material which will conduct electricity such as a suitable metal. The wires 25 are connected to the bars through the medium of the securing elements or bolts 24.

As shown in the drawings, the sphere or ball 30 is arranged so that there is a slight clearance between the body member and the housing 15. The bleeding aperture 28 is arranged above the center of the ball 30.

By means of the present invention, it will be seen that there has been provided a switch which can be used for opening an electrical circuit or closing an electrical circuit or whereby these can be accomplished simultaneously Whenever the desired or required air flow passes through the Venturi 10.

As the air passes through the Venturi 10, the air pressure is reduced in the throat 12 and in the orifice 14, and chamber or space 32. The normal air pressure in the space or chamber 33 forces the spherical body member 30 up away from the contacts 22 and 23 so that this body member moves against the contacts 19 and 18 and this compresses the spring 31. Thus, the circuit between the contacts 22 and 23 is opened, and the circuit between the contacts or bars 19 and 18 is closed.

When the air flow through the Venturi 19 decreases or stops, the body member 30 again moves away from the bars 19 and 18 and engages the bars or contacts 22 and 23.

The bleed opening 28 permits the partial vacuum in 'bars are also made of metal and the wires are connected to the bars by means of binding screws. The vent 27 opens to the atmosphere, and the spring 31 is a light compression type of spring which serves to prevent the sphere 30 from bouncing on the contacts. The bleed 28 also opens to the atmosphere, and the chamber 32 is a vacuum chamber, while the chamber 33 is at normal atmospheric pressure.

I claim:

1. Ina switch, a Venturi including an intermediate narrow portion defining a throat, the ends of said Venturi being enlarged and being open, there being an orifice in said throat intermediate the ends of said Venturi, a housing depending from said Venturi and secured thereto, a first pair of opposed bushings mounted in said housing, a second pair of opposed bushings mounted in said housing, a contact bar mounted in each of said bushings, a securing element connected to each contact bar, wires connected to said securing elements, a spherical body member movably mounted in said housing and mounted for movement into and out of engagement with said contact bars, a coil spring engaging said body member and interposed between said first named bushings and said body member, there being an aperture in said housing intermediate the ends thereof, and a neck depending from the lower end of said housing and provided with a vent.

2. In a switch, a Venturi including an intermediate narrow portion defining a throat, the ends of said Vengaging said body member to prevent said body member turi being enlarged and being open, there being an orifice in said throat intermediate the ends of said Venturi, a housing depending from said Venturi and secured thereto, a first pair of opposed bushings mounted in said housing, a second pair of opposed bushings mounted in said housing, a contact bar mounted in each of said bushings, a securing element connected to each contact bar, wires connected to said securing elements, a spherical body member movably mounted in said housing and mounted for movement into and out of engagement with said contact bars, a coil spring engaging said body member and interposed between said first named bushings and said body member, there being an aperture in said housing intermediate the ends thereof, and a neck depending from the lower end of said housing and provided with a vent, said Venturi and housing being made of non-conductive material.

3. The structure as defined in claim 2, wherein the inner ends of said contact bars are beveled.

4. In combination, a Venturi, a housing extending from said Venturi, there being an orifice in said Venturi establishing communication between said housing and Venturi, a plurality of contact bars carried by said housing, a spherical body member movably mounted in said housing and mounted for movement into and out of engagement with said contact bars, and a coil spring enfrom bouncing on the contact bars.

.References Cited in the file of this patent UNITED STATES PATENTS 2,096,125 McDougall Oct. 19, 1937 2,339,087 Mantz Jan. 11, 1944 FOREIGN PATENTS 7 854,131 France Jan. 4, 1944 

